Extraction of coal



Patented June 15, 1954 EXTRACTION F COAL Louis E. Ruidlsch, Wappingers Falls, and Ernest Y., assignors to The Texas F. Pevere, Beacon, N. Company, New York,

Delaware N. Y., a corporation of No Drawing. Application February 8, 1952, Serial No. 270,754

4 Claims.

This invention relates to the extraction of coal and contemplates the production of a liquid extract from coal by treating it with hydrogenated thianaphthene.

In accordance with the invention it has been discovered that hydrogenated thianaphthene, such as dihydrothianaphthene, is a superior treating agent for the recovery of the liquid components of coal. In practicing the invention the coal is digested with the hydrogenated thianaphthene at elevated temperatures to effect recovery of liquid constituents. It is found that the action of the hydrogenated thianaphthene on the coal goes beyond that of a mere solvent effect since the hydrogenated thianaphthenes appear to serve as a carrier of active hydrogen, and a hydrogen exchange reaction in addition to the solvent action takes place so as to produce very high yields of recovered extract.

The coal preferably in a pulverized form is digested with hydrogenated thianaphthene, such as dihydrothianaphthene, at elevated temperatures of the order of 600 F. and 700 F'. The digestion is conducted without release of gas in order to promote the hydrogenating or hydrogen transfer reaction. The solvent is preferably used in weight proportions somewhat in excess of that of the coal.

In a typical example of the invention 150 grams of bituminous coal of -50 mesh and 300 grams of dihydrothianaphthene were charged to a bomb. The bomb was heated in a rocking sleeve heater to 650 F. and held at this temperature for two hours. The pressure rose to a maximum of 300 lbs. per square inch indicating the release of hydrogen from the solvent. After cooling, the contents of the bomb were washed out with benzene and the whole mass both solid and liquid was poured into the thimble of a Soxhlet extractor and extracted with benzene. The solids recovered were dried to constant weight. This material which was considered as unextracted coal amounted to 106 grams. The extract was distilled to remove the benzene and the extraction solvent was removed by distillation under reduced pressure. The recovered extract amounted to 41 grams. Thus the percentage of coal extracted was 29% and the weight per cent 0! the recovered extract based on the coal charge was 27%.

Although a preferred embodiment of the invention has been described herein, it will be understood that various changes and modifications may be made therein, while securing to a greater or less extent some or all of the benefits of the invention, without departing from the spirit and scope thereof.

We claim:

1. The process of treating coal to recover liquid constituents therefrom that comprises digesting the coal with a solvent consisting essentially of hydrogenated thianaphthene under superatmospherio pressure and elevated temperature.

2. The process of treating coal to recover liquid constituents therefrom that comprises digesting the coal with a solvent consisting essentially of hydrogenated thianaphthene at a temperature adequate to effect the release of hydrogen from the hydrogenated thianaphthene and under a maintained pressure of the released hydrogen.

3. The process of treating coal to recover liquid constituents therefrom that comprises digesting the coal with a solvent consisting essentially of dihydronaphthene under superatmospheric pressure and elevated temperature.

4. The process of treating coal to recover liquid constituents therefrom that comprises subjecting the coal in the presence of a solvent consisting essentially of dihydrothianaphthene in a closed container to digestion at temperatures of the order of 600 F. and 700 F. under the resultant pressure generated by the temperature.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES The Merck Index, 6th ed., page 949. Publlshed by Merck and Company, Inc., Railway, New Jersey, U.S.A., 1952. 

1. THE PROCESS OF TREATING COAL TO RECOVER LIQUID CONSTITUENTS THEREFROM THAT COMPRISES DIGESTING THE COAL WITH A SOLVENT CONSISTING ESSENTIALLY OF HYDROGENATED THIANAPHTHENE UNDER SUPERATMOSPHERIC PRESSURE AND ELEVATED TEMPERATURE. 